While doing a WFR recert years ago, the instructor was of the opinion that alcohol hand sanitizer's benefits were almost totally psychosomatic. Now it's ubiquitous and I have to go about the world smelling it. Ick.

Aaaahhhh....I fell prey to the whole "hand sanitizers kill every germ known to man" fallacy. I used to use it routinely, until I ended up with a horrific rash, cracks, bleeding, and peeling skin that looked like leprosy. The doctor took one look at my hands and without me saying a word, exclaimed, "Use a lot of hand sanitizer, huh?" He then gave me the sage advice that only a seasoned medical professional could give. "Stop doing that."

The older I get, the more this becomes true. It seems that we find scientific studies and reasons why Grammy was right... eating your veggies, eat the skin of the fruit, wash your hands with soap and water.

Good article. I have often tried to convince my hiking buddies that you are at more of a risk of a GI infection from not washing your hands than debating the efficacies of the many water treatment options.

There is no single means of cleaning hands which is a "magic bullet." Efficacy varies depending upon the pathogen and user technique and the sanitizing agent used.

See the references which correspond to the following findings:

1) Compared to rubbing with an antibacterial liquid with a water rinse only, an alcohol-based hand sanitizer was relatively ineffective against norovirus.

2) 62% alcohol foams were only somewhat more effective than water against E. coli, because the time required for dryness often exceeds the recommended 30 seconds resulted in a small amount being used.

3) Alcohol based hand sanitizer was significantly better than soap and water with respect to reduction in levels of fecal streptococci.

4) An alcohol-based hand sanitizer with polyquaternium polymer and organic acid was superior to alcohol sanitzer against enteric viruses.

5) Antimicrobial handwashing agents were the most efficacious in bacterial removal, whereas waterless agents showed variable efficacy. Alcohol-based handrubs compared with other products demonstrated better efficacy after a single episode of hand hygiene than after 10 episodes. Effective hand hygiene for high levels of viral contamination with a nonenveloped virus was best achieved by physical removal with a nonantimicrobial soap or tap water alone.

REFERENCES

1) Appl Environ Microbiol. 2010 Jan;76(2):394-9. Epub 2009 Nov 20.

Effectiveness of liquid soap and hand sanitizer against Norwalk virus on contaminated hands.

Disinfection is an essential measure for interrupting human norovirus (HuNoV) transmission, but it is difficult to evaluate the efficacy of disinfectants due to the absence of a practicable cell culture system for these viruses. The purpose of this study was to screen sodium hypochlorite and ethanol for efficacy against Norwalk virus (NV) and expand the studies to evaluate the efficacy of antibacterial liquid soap and alcohol-based hand sanitizer for the inactivation of NV on human finger pads. Samples were tested by real-time reverse transcription-quantitative PCR (RT-qPCR) both with and without a prior RNase treatment. In suspension assay, sodium hypochlorite concentrations of >or=160 ppm effectively eliminated RT-qPCR detection signal, while ethanol, regardless of concentration, was relatively ineffective, giving at most a 0.5 log(10) reduction in genomic copies of NV cDNA. Using the American Society for Testing and Materials (ASTM) standard finger pad method and a modification thereof (with rubbing), we observed the greatest reduction in genomic copies of NV cDNA with the antibacterial liquid soap treatment (0.67 to 1.20 log(10) reduction) and water rinse only (0.58 to 1.58 log(10) reduction). The alcohol-based hand sanitizer was relatively ineffective, reducing the genomic copies of NV cDNA by only 0.14 to 0.34 log(10) compared to baseline. Although the concentrations of genomic copies of NV cDNA were consistently lower on finger pad eluates pretreated with RNase compared to those without prior RNase treatment, these differences were not statistically significant. Despite the promise of alcohol-based sanitizers for the control of pathogen transmission, they may be relatively ineffective against the HuNoV, reinforcing the need to develop and evaluate new products against this important group of viruses.

BACKGROUND: Foams containing 62% ethanol are used for hand decontamination in many countries. A long drying time may reduce the compliance of healthcare workers in applying the recommended amount of foam. Therefore, we have investigated the correlation between the applied amount and drying time, and the bactericidal efficacy of ethanol foams.

METHODS: In a first part of tests, four foams (Alcare plus, Avagard Foam, Bode test foam, Purell Instant Hand Sanitizer) containing 62% ethanol, which is commonly used in U.S. hospitals, were applied to 14 volunteers in a total of seven variations, to measure drying times. In a second part of tests, the efficacy of the established amount of foam for a 30 s application time of two foams (Alcare plus, Purell Instant Hand Sanitizer) and water was compared to the EN 1500 standard of 2 x 3 mL applications of 2-propanol 60% (v/v), on hands artificially contaminated with Escherichia coli. Each application used a cross-over design against the reference alcohol with 15 volunteers.

RESULTS: The mean weight of the applied foam varied between 1.78 and 3.09 g, and the mean duration to dryness was between 37 s and 103 s. The correlation between the amount of foam applied and time until hands felt dry was highly significant (p < 0.001; Pearson's correlation coefficient: 0.724; 95% confidence interval: 0.52-0.93). By linear correlation, 1.6 g gave an intercept of a 30 s application time. Application of 1.6 g of Purell Instant Hand Sanitizer (mean log10-reduction: 3.05 +/- 0.45) and Alcare plus (3.58 +/- 0.71) was significantly less effective than the reference disinfection (4.83 +/- 0.89 and 4.60 +/- 0.59, respectively; p < 0.001). Application of 1.6 g of water gave a mean log10-reduction of 2.39 +/- 0.57.

CONCLUSIONS: When using 62% ethanol foams, the time required for dryness often exceeds the recommended 30 s. Therefore, only a small volume is likely to be applied in clinical practice. Small amounts, however, failed to meet the efficacy requirements of EN 1500 and were only somewhat more effective than water.

Free full text @http://www.biomedcentral.com/1471-2334/10/78- - - -

3) Am J Trop Med Hyg. 2010 Feb;82(2):270-8.

Efficacy of waterless hand hygiene compared with handwashing with soap: a field study in Dar es Salaam, Tanzania

Pickering AJ, Boehm AB, Mwanjali M, Davis J

Emmett Interdisciplinary Program in Environment and Resources, School of Earth Sciences and Civil and Environmental Engineering, and Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA. amyjanel@stanford.edu

Abstract

Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed.

Norovirus is the leading cause of food-related illness in the United States, and contamination of ready-to-eat items by food handlers poses a high risk for disease. This study reports the in vitro (suspension test) and in vivo (fingerpad protocol) assessments of a new ethanol-based hand sanitizer containing a synergistic blend of polyquaternium polymer and organic acid, which is active against viruses of public health importance, including norovirus. When tested in suspension, the test product reduced the infectivity of the nonenveloped viruses human rotavirus (HRV), poliovirus type 1 (PV-1), and the human norovirus (HNV) surrogates feline calicivirus (FCV) F-9 and murine norovirus type 1 (MNV-1) by greater than 3 log(10) after a 30-s exposure. In contrast, a benchmark alcohol-based hand sanitizer reduced only HRV by greater than 3 log(10) and none of the additional viruses by greater than 1.2 log(10) after the same exposure. In fingerpad experiments, the test product produced a 2.48 log(10) reduction of MNV-1 after a 30-s exposure, whereas a 75% ethanol control produced a 0.91 log(10) reduction. Additionally, the test product reduced the infectivity titers of adenovirus type 5 (ADV-5) and HRV by > or =3.16 log(10) and > or =4.32 log(10), respectively, by the fingerpad assay within 15 s; and PV-1 was reduced by 2.98 log(10) in 30 s by the same method. Based on these results, we conclude that this new ethanol-based hand sanitizer is a promising option for reducing the transmission of enteric viruses, including norovirus, by food handlers and care providers.

Free full text @http://aem.asm.org/cgi/content/full/74/16/5047- - - -

5) Am J Infect Control. 2005 Mar;33(2):67-77

Comparative efficacy of hand hygiene agents in the reduction of bacteria and viruses.

METHODS: We studied the efficacy of hand hygiene agents (n = 14) following 10-second applications to reduce the level of challenge organisms (Serratia marcescens and MS2 bacteriophage) from the hands of healthy volunteers using the ASTM-E-1174-94 test method.

RESULTS: The highest log 10 reductions of S marcescens were achieved with agents containing chlorhexidine gluconate (CHG), triclosan, benzethonium chloride, and the controls, tap water alone and nonantimicrobial soap and water (episode 1 of hand hygiene, 1.60-2.01; episode 10, 1.60-3.63). Handwipes but not alcohol-based handrubs were significantly inferior from these agents after a single episode of hand hygiene, but both groups were significantly inferior after 10 episodes. After a single episode of hand hygiene, alcohol/silver iodide, CHG, triclosan, and benzethonium chloride were similar to the controls in reduction of MS2, but, in general, handwipes and alcohol-based handrubs showed significantly lower efficacy. After 10 episodes, only benzethonium chloride (1.33) performed as well as the controls (1.59-1.89) in the reduction of MS2.

CONCLUSIONS: Antimicrobial handwashing agents were the most efficacious in bacterial removal, whereas waterless agents showed variable efficacy. Alcohol-based handrubs compared with other products demonstrated better efficacy after a single episode of hand hygiene than after 10 episodes. Effective hand hygiene for high levels of viral contamination with a nonenveloped virus was best achieved by physical removal with a nonantimicrobial soap or tap water alone.

Abstract and link for full text purchase:http://www.ajicjournal.org/article/S0196-6553(04)00587-5

Our outfitter for a Kilimanjaro climb carried bleach (a brand used locally to sterilize infant formula bottles) and prepared a dilute solution before meals for the cooking staff and guests to use prior to meal prep and eating. Though it leaves a slight chlorine smell until thoroughly dried, it seems to be an effective and readily available antimicrobial treatment.

Ryan - great article. Funny lead in. I once read the introduction of soap saved more children from infection and childhood death in third world countries than any other thing. Then as a paramedic I was taught that hand sanitizers were only good if nothing else was available and to wash your hands as soon as possible after application. So I use Dr. Bronner's when backpacking and when traveling internationally. I even wash my clothes in it when I have to do them by hand.

Ryan, skin that is prone to cracking can be a sign of Vitamin A deficiency, and I wonder if that is a factor for you? Due to my work, I use EtOH sanitizer on my hands 25+ times a day on my hands and I notice no drying or cracking effects at all.

OK, that's it. Out with the stupid alcohol sanitizer... I've been waiting for this justification. I'll go get some castile bar soaps at Walgreens or something. I'm also sick of liquid soaps which are somewhat expensive considering how fast they run out when you let others in the group use it too. I always liked bar soaps in the shower and on the bathroom sink anyways.

"Illegal immigrants as metaphor for fecal matter and bacteria? Really? Thought Ryan was smarter than that."

Thanks Ryan for being a voice of reason in the current trend of (over) use of alcohol-based sanitizers. If I've just touched something that is likely to make me ill, I want to remove this contamination from my skin, not just spread it all over both hands and hope that I used enough alcohol to really sterilize everything. While I do carry and use soap, more often than not I instead choose to use a technique my dad taught me when I was a kid- to use mud, sand, clay, or even just dirt with a bit of water to scrub my hands, then rinse them off with a bit of water. I find this technique works really well no matter what kind of crud you're trying to remove. Just how "sterile" a mud scrub can make your hands is up for debate, but my hands definitely feel cleaner using this method vs. using just soap & water. Anyone else out there use the mud scrub method?

Thanks Ryan for this timely posting. I have used the alcohol gels in my potty kit for years with little of the effects you discuss. I think largely because I use my kit perhaps once a day.However, hand sanitizing is an important issue and I have found a method which work for me. I use the granulated chlorine used for pool disinfection which can be found in any pool supply store, Target or Walmart for regular hand sanitation around camp. Here is what I do:When I get to camp I haul up about 40oz of water and empty it into a camp bowl I have constructed from a Sea to Summit kitchen sink. The bowl weighs about 3.5oz. I then sprinkle about 1/8 teaspoon of granulated chlorine into the water and swish it around until dissolved. Then I rinse my hands in the strong solution and set about my camp chores. Before preparing meals I again rinse my hands in the solution and wash with camp soap. After dinner I add more camp soap to the solution and wash my dishes. Then a refill of the bowl with fresh water and more chlorine and a final rinse. The chlorine removes any and all food odors completely and the now clean dishes are bandana dried and set out for the morning. I also use this same water if I have to use my potty kit while in camp. I have been doing this for many years and it has worked to keep me healthy. Incidentally, a stronger solution can be made which is useful in disinfecting medical implements if necessary. I have also used the clean solution to wash my underarms to remove the stink. Works wonders for this application.